Evolution of the Raman 2D’ mode in monolayer graphene during electrochemical doping

•The quantification and control of the charge carrier concentration in graphene is important for many applications. This problem is typically addressed by study of the G mode. However, in some cases this is not a convenient approach. Here, we present in situ Raman spectroelectrochemical study of the behavior of the 2D’ mode of graphene single layer during electrochemical charging. We demonstrate that the 2D’ mode also provides useful information for quantification of charge carrier concentration in graphene. The important changes are observed in the frequency of this mode especially at higher doping levels. We believe that our work can be useful for broad range of graphene studies, where the charge carrier concentration plays important role.